Soy wax
A vegetable wax made from soybean oil; it burns slowly and cleanly and holds fragrance well, which is why most hand-poured candles use it.
Soy wax is hydrogenated soybean oil. Compared with paraffin it melts at a lower temperature, so a soy candle burns more slowly and creates a wide, even melt pool that releases fragrance gently. It is softer, which suits containers (jars and tins) better than free-standing shapes; pillars use harder soy blends.
Soy has a 'memory': the first burn decides how it melts afterwards, so always let the first melt reach the edges.